-#include <stdlib.h>
+/** @file threads.cc
+ * @brief Thread functions.
+ */
-#include "libthreads.h"
-#include "schedule.h"
+#include <string.h>
+
+#include <threads.h>
+#include "mutex.h"
#include "common.h"
-#include "threads_internal.h"
+#include "threads-model.h"
+#include "action.h"
/* global "model" object */
#include "model.h"
+#include "execution.h"
+#include "schedule.h"
+#include "clockvector.h"
-#define STACK_SIZE (1024 * 1024)
+#include <dlfcn.h>
+
+#ifdef TLS
+uintptr_t get_tls_addr() {
+ uintptr_t addr;
+ asm ("mov %%fs:0, %0" : "=r" (addr));
+ return addr;
+}
+
+#include <asm/prctl.h>
+#include <sys/prctl.h>
+extern "C" {
+int arch_prctl(int code, unsigned long addr);
+}
+static void set_tls_addr(uintptr_t addr) {
+ arch_prctl(ARCH_SET_FS, addr);
+ asm ("mov %0, %%fs:0" : : "r" (addr) : "memory");
+}
+#endif
-static void *stack_allocate(size_t size)
+/** Allocate a stack for a new thread. */
+static void * stack_allocate(size_t size)
{
- return malloc(size);
+ return Thread_malloc(size);
}
+/** Free a stack for a terminated thread. */
static void stack_free(void *stack)
{
- free(stack);
+ Thread_free(stack);
+}
+
+/**
+ * @brief Get the current Thread
+ *
+ * Must be called from a user context
+ *
+ * @return The currently executing thread
+ */
+Thread * thread_current(void)
+{
+ ASSERT(model);
+ return model->get_current_thread();
+}
+
+/**
+ * @brief Get the current Thread id
+ *
+ * Must be called from a user context
+ *
+ * @return The id of the currently executing thread
+ */
+thread_id_t thread_current_id(void)
+{
+ ASSERT(model);
+ return model->get_current_thread_id();
+}
+
+void modelexit() {
+ model->switch_thread(new ModelAction(THREAD_FINISH, std::memory_order_seq_cst, thread_current()));
+}
+
+void initMainThread() {
+ atexit(modelexit);
+ Thread * curr_thread = thread_current();
+ model->switch_thread(new ModelAction(THREAD_START, std::memory_order_seq_cst, curr_thread));
}
-Thread *thread_current(void)
+/**
+ * Provides a startup wrapper for each thread, allowing some initial
+ * model-checking data to be recorded. This method also gets around makecontext
+ * not being 64-bit clean
+ */
+void thread_startup()
{
- return model->scheduler->get_current_thread();
+ Thread * curr_thread = thread_current();
+#ifndef TLS
+ /* Add dummy "start" action, just to create a first clock vector */
+ model->switch_thread(new ModelAction(THREAD_START, std::memory_order_seq_cst, curr_thread));
+#endif
+
+ /* Call the actual thread function */
+ if (curr_thread->start_routine != NULL) {
+ curr_thread->start_routine(curr_thread->arg);
+ } else if (curr_thread->pstart_routine != NULL) {
+ // set pthread return value
+ void *retval = curr_thread->pstart_routine(curr_thread->arg);
+ curr_thread->set_pthread_return(retval);
+ }
+#ifndef TLS
+ /* Finish thread properly */
+ model->switch_thread(new ModelAction(THREAD_FINISH, std::memory_order_seq_cst, curr_thread));
+#endif
+}
+
+
+static int (*real_epoll_wait_p)(int epfd, struct epoll_event *events, int maxevents, int timeout) = NULL;
+
+int real_epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout) {
+ return real_epoll_wait_p(epfd, events, maxevents, timeout);
+}
+
+static int (*pthread_mutex_init_p)(pthread_mutex_t *__mutex, const pthread_mutexattr_t *__mutexattr) = NULL;
+
+int real_pthread_mutex_init(pthread_mutex_t *__mutex, const pthread_mutexattr_t *__mutexattr) {
+ return pthread_mutex_init_p(__mutex, __mutexattr);
+}
+
+static int (*pthread_mutex_lock_p) (pthread_mutex_t *__mutex) = NULL;
+
+int real_pthread_mutex_lock (pthread_mutex_t *__mutex) {
+ return pthread_mutex_lock_p(__mutex);
+}
+
+static int (*pthread_mutex_unlock_p) (pthread_mutex_t *__mutex) = NULL;
+
+int real_pthread_mutex_unlock (pthread_mutex_t *__mutex) {
+ return pthread_mutex_unlock_p(__mutex);
+}
+
+static int (*pthread_create_p) (pthread_t *__restrict, const pthread_attr_t *__restrict, void *(*)(void *), void * __restrict) = NULL;
+
+int real_pthread_create (pthread_t *__restrict __newthread, const pthread_attr_t *__restrict __attr, void *(*__start_routine)(void *), void *__restrict __arg) {
+ return pthread_create_p(__newthread, __attr, __start_routine, __arg);
+}
+
+static int (*pthread_join_p) (pthread_t __th, void ** __thread_return) = NULL;
+
+int real_pthread_join (pthread_t __th, void ** __thread_return) {
+ return pthread_join_p(__th, __thread_return);
+}
+
+static void (*pthread_exit_p)(void *) __attribute__((noreturn))= NULL;
+
+void real_pthread_exit (void * value_ptr) {
+ pthread_exit_p(value_ptr);
+}
+
+void real_init_all() {
+ char * error;
+ if (!real_epoll_wait_p) {
+ real_epoll_wait_p = (int (*)(int epfd, struct epoll_event *events, int maxevents, int timeout))dlsym(RTLD_NEXT, "epoll_wait");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
+ if (!pthread_mutex_init_p) {
+ pthread_mutex_init_p = (int (*)(pthread_mutex_t *__mutex, const pthread_mutexattr_t *__mutexattr))dlsym(RTLD_NEXT, "pthread_mutex_init");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
+ if (!pthread_mutex_lock_p) {
+ pthread_mutex_lock_p = (int (*)(pthread_mutex_t *__mutex))dlsym(RTLD_NEXT, "pthread_mutex_lock");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
+ if (!pthread_mutex_unlock_p) {
+ pthread_mutex_unlock_p = (int (*)(pthread_mutex_t *__mutex))dlsym(RTLD_NEXT, "pthread_mutex_unlock");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
+ if (!pthread_create_p) {
+ pthread_create_p = (int (*)(pthread_t *__restrict, const pthread_attr_t *__restrict, void *(*)(void *), void *__restrict))dlsym(RTLD_NEXT, "pthread_create");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
+ if (!pthread_join_p) {
+ pthread_join_p = (int (*)(pthread_t __th, void ** __thread_return))dlsym(RTLD_NEXT, "pthread_join");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ if (!pthread_exit_p) {
+ *((void (**)(void *)) &pthread_exit_p) = (void (*)(void *))dlsym(RTLD_NEXT, "pthread_exit");
+ if ((error = dlerror()) != NULL) {
+ fputs(error, stderr);
+ exit(EXIT_FAILURE);
+ }
+ }
}
+#ifdef TLS
+void finalize_helper_thread() {
+ Thread * curr_thread = thread_current();
+ real_pthread_mutex_lock(&curr_thread->mutex);
+ curr_thread->tls = (char *) get_tls_addr();
+ real_pthread_mutex_unlock(&curr_thread->mutex);
+ //Wait in the kernel until it is time for us to finish
+ real_pthread_mutex_lock(&curr_thread->mutex2);
+ real_pthread_mutex_unlock(&curr_thread->mutex2);
+ //return to helper thread function
+ setcontext(&curr_thread->context);
+}
+
+void * helper_thread(void * ptr) {
+ Thread * curr_thread = thread_current();
+
+ //build a context for this real thread so we can take it's context
+ int ret = getcontext(&curr_thread->helpercontext);
+ ASSERT(!ret);
+
+ //Setup destructor
+ if (pthread_setspecific(model->get_execution()->getPthreadKey(), (const void *)4)) {
+ printf("Destructor setup failed\n");
+ exit(-1);
+ }
+
+
+ /* Initialize new managed context */
+ curr_thread->helper_stack = stack_allocate(STACK_SIZE);
+ curr_thread->helpercontext.uc_stack.ss_sp = curr_thread->helper_stack;
+ curr_thread->helpercontext.uc_stack.ss_size = STACK_SIZE;
+ curr_thread->helpercontext.uc_stack.ss_flags = 0;
+ curr_thread->helpercontext.uc_link = NULL;
+ makecontext(&curr_thread->helpercontext, finalize_helper_thread, 0);
+
+ model_swapcontext(&curr_thread->context, &curr_thread->helpercontext);
+
+
+ //start the real thread
+ thread_startup();
+
+ return NULL;
+}
+
+#ifdef TLS
+void tlsdestructor(void *v) {
+ uintptr_t count = (uintptr_t) v;
+ if (count > 1) {
+ if (pthread_setspecific(model->get_execution()->getPthreadKey(), (const void *)(count - 1))) {
+ printf("Destructor setup failed\n");
+ exit(-1);
+ }
+ return;
+ }
+ /* Finish thread properly */
+ model->switch_thread(new ModelAction(THREAD_FINISH, std::memory_order_seq_cst, thread_current()));
+}
+#endif
+
+void setup_context() {
+ Thread * curr_thread = thread_current();
+
+ /* Add dummy "start" action, just to create a first clock vector */
+ model->switch_thread(new ModelAction(THREAD_START, std::memory_order_seq_cst, curr_thread));
+
+ real_init_all();
+
+ /* Initialize our lock */
+ real_pthread_mutex_init(&curr_thread->mutex, NULL);
+ real_pthread_mutex_init(&curr_thread->mutex2, NULL);
+ real_pthread_mutex_lock(&curr_thread->mutex2);
+
+ /* Create the real thread */
+ real_pthread_create(&curr_thread->thread, NULL, helper_thread, NULL);
+ bool notdone = true;
+ while(notdone) {
+ real_pthread_mutex_lock(&curr_thread->mutex);
+ if (curr_thread->tls != NULL)
+ notdone = false;
+ real_pthread_mutex_unlock(&curr_thread->mutex);
+ }
+
+ set_tls_addr((uintptr_t)curr_thread->tls);
+ setcontext(&curr_thread->context);
+}
+#endif
+
+/**
+ * Create a thread context for a new thread so we can use
+ * setcontext/getcontext/swapcontext to swap it out.
+ * @return 0 on success; otherwise, non-zero error condition
+ */
int Thread::create_context()
{
int ret;
if (ret)
return ret;
- /* start_routine == NULL means this is our initial context */
- if (!start_routine)
- return 0;
-
/* Initialize new managed context */
stack = stack_allocate(STACK_SIZE);
context.uc_stack.ss_sp = stack;
context.uc_stack.ss_size = STACK_SIZE;
context.uc_stack.ss_flags = 0;
- context.uc_link = &model->system_thread->context;
- makecontext(&context, start_routine, 1, arg);
+ context.uc_link = NULL;
+#ifdef TLS
+ makecontext(&context, setup_context, 0);
+#else
+ makecontext(&context, thread_startup, 0);
+#endif
return 0;
}
-int Thread::swap(Thread *t)
+/**
+ * Swaps the current context to another thread of execution. This form switches
+ * from a user Thread to a system context.
+ * @param t Thread representing the currently-running thread. The current
+ * context is saved here.
+ * @param ctxt Context to which we will swap. Must hold a valid system context.
+ * @return Does not return, unless we return to Thread t's context. See
+ * swapcontext(3) (returns 0 for success, -1 for failure).
+ */
+int Thread::swap(Thread *t, ucontext_t *ctxt)
{
- return swapcontext(&this->context, &t->context);
+ t->set_state(THREAD_READY);
+#ifdef TLS
+ set_tls_addr((uintptr_t)model->getInitThread()->tls);
+#endif
+ return model_swapcontext(&t->context, ctxt);
}
-void Thread::dispose()
+/**
+ * Swaps the current context to another thread of execution. This form switches
+ * from a system context to a user Thread.
+ * @param ctxt System context variable to which to save the current context.
+ * @param t Thread to which we will swap. Must hold a valid user context.
+ * @return Does not return, unless we return to the system context (ctxt). See
+ * swapcontext(3) (returns 0 for success, -1 for failure).
+ */
+int Thread::swap(ucontext_t *ctxt, Thread *t)
{
- DEBUG("completed thread %d\n", thread_current()->get_id());
- state = THREAD_COMPLETED;
- stack_free(stack);
+ t->set_state(THREAD_RUNNING);
+#ifdef TLS
+ if (t->tls != NULL)
+ set_tls_addr((uintptr_t)t->tls);
+#endif
+ return model_swapcontext(ctxt, &t->context);
}
-Thread::Thread(thrd_t *t, void (*func)(), void *a) {
- int ret;
+int Thread::swap(Thread *t, Thread *t2)
+{
+ t2->set_state(THREAD_RUNNING);
+ if (t == t2)
+ return 0;
- user_thread = t;
- start_routine = func;
- arg = a;
+#ifdef TLS
+ if (t2->tls != NULL)
+ set_tls_addr((uintptr_t)t2->tls);
+#endif
+ return model_swapcontext(&t->context, &t2->context);
+}
- /* Initialize state */
- ret = create_context();
- if (ret)
- printf("Error in create_context\n");
+/** Terminate a thread. */
+void Thread::complete()
+{
+ ASSERT(!is_complete());
+ DEBUG("completed thread %d\n", id_to_int(get_id()));
+ state = THREAD_COMPLETED;
+}
- state = THREAD_CREATED;
- model->assign_id(this);
- model->scheduler->add_thread(this);
+void Thread::freeResources() {
+ if (stack)
+ stack_free(stack);
+#ifdef TLS
+ if (this != model->getInitThread()) {
+ real_pthread_mutex_unlock(&mutex2);
+ real_pthread_join(thread, NULL);
+ stack_free(helper_stack);
+ }
+#endif
+ state = THREAD_FREED;
}
-Thread::Thread(thrd_t *t) {
- /* system thread */
- user_thread = t;
- state = THREAD_CREATED;
- model->assign_id(this);
- create_context();
- model->add_system_thread(this);
+/**
+ * @brief Construct a new model-checker Thread
+ *
+ * A model-checker Thread is used for accounting purposes only. It will never
+ * have its own stack, and it should never be inserted into the Scheduler.
+ *
+ * @param tid The thread ID to assign
+ */
+Thread::Thread(thread_id_t tid) :
+ parent(NULL),
+ acq_fence_cv(new ClockVector()),
+ creation(NULL),
+ pending(NULL),
+ wakeup_state(false),
+ start_routine(NULL),
+ arg(NULL),
+ stack(NULL),
+#ifdef TLS
+ tls(NULL),
+#endif
+ user_thread(NULL),
+ id(tid),
+ state(THREAD_READY), /* Thread is always ready? */
+ last_action_val(0),
+ model_thread(true)
+{
+ // real_memset is not defined when
+ // the model thread is constructed
+ memset(&context, 0, sizeof(context));
}
-thread_id_t Thread::get_id()
+/**
+ * Construct a new thread.
+ * @param t The thread identifier of the newly created thread.
+ * @param func The function that the thread will call.
+ * @param a The parameter to pass to this function.
+ */
+Thread::Thread(thread_id_t tid, thrd_t *t, void (*func)(void *), void *a, Thread *parent) :
+ parent(parent),
+ acq_fence_cv(new ClockVector()),
+ creation(NULL),
+ pending(NULL),
+ wakeup_state(false),
+ start_routine(func),
+ pstart_routine(NULL),
+ arg(a),
+#ifdef TLS
+ tls(NULL),
+#endif
+ user_thread(t),
+ id(tid),
+ state(THREAD_CREATED),
+ last_action_val(VALUE_NONE),
+ model_thread(false)
{
- return thrd_to_id(*user_thread);
+ int ret;
+
+ /* Initialize state */
+ ret = create_context();
+ if (ret)
+ model_print("Error in create_context\n");
+
+ user_thread->priv = this; // WL
}
-/*
- * Return 1 if found next thread, 0 otherwise
+/**
+ * Construct a new thread for pthread.
+ * @param t The thread identifier of the newly created thread.
+ * @param func The function that the thread will call.
+ * @param a The parameter to pass to this function.
*/
-static int thread_system_next(void)
-{
- Thread *curr, *next;
-
- curr = thread_current();
- model->check_current_action();
- if (curr) {
- if (curr->get_state() == THREAD_READY)
- model->scheduler->add_thread(curr);
- else if (curr->get_state() == THREAD_RUNNING)
- /* Stopped while running; i.e., completed */
- curr->dispose();
- else
- DEBUG("ERROR: current thread in unexpected state??\n");
- }
- next = model->scheduler->next_thread();
- if (next)
- next->set_state(THREAD_RUNNING);
- DEBUG("(%d, %d)\n", curr ? curr->get_id() : -1, next ? next->get_id() : -1);
- if (!next)
- return 1;
- return model->system_thread->swap(next);
+Thread::Thread(thread_id_t tid, thrd_t *t, void *(*func)(void *), void *a, Thread *parent) :
+ parent(parent),
+ acq_fence_cv(new ClockVector()),
+ creation(NULL),
+ pending(NULL),
+ wakeup_state(false),
+ start_routine(NULL),
+ pstart_routine(func),
+ arg(a),
+#ifdef TLS
+ tls(NULL),
+#endif
+ user_thread(t),
+ id(tid),
+ state(THREAD_CREATED),
+ last_action_val(VALUE_NONE),
+ model_thread(false)
+{
+ int ret;
+
+ /* Initialize state */
+ ret = create_context();
+ if (ret)
+ model_print("Error in create_context\n");
}
-static void thread_wait_finish(void)
+
+/** Destructor */
+Thread::~Thread()
{
+ if (!is_complete())
+ complete();
- DBG();
+ delete acq_fence_cv;
+}
- while (!thread_system_next());
+/** @return The thread_id_t corresponding to this Thread object. */
+thread_id_t Thread::get_id() const
+{
+ return id;
}
-/*
- * Main system function
+/**
+ * Set a thread's THREAD_* state (@see thread_state)
+ * @param s The state to enter
*/
-int main()
+void Thread::set_state(thread_state s)
{
- thrd_t user_thread, main_thread;
- Thread *th;
-
- model = new ModelChecker();
+ ASSERT(s == THREAD_COMPLETED || state != THREAD_COMPLETED);
+ state = s;
+}
- th = new Thread(&main_thread);
+/**
+ * Get the Thread that this Thread is immediately waiting on
+ * @return The thread we are waiting on, if any; otherwise NULL
+ */
+Thread * Thread::waiting_on() const
+{
+ if (!pending)
+ return NULL;
- /* Start user program */
- thrd_create(&user_thread, &user_main, NULL);
+ switch (pending->get_type()) {
+ case THREAD_JOIN:
+ case PTHREAD_JOIN:
+ return pending->get_thread_operand();
+ case ATOMIC_LOCK:
+ return (Thread *)pending->get_mutex()->get_state()->locked;
+ default:
+ return NULL;
+ }
+}
- /* Wait for all threads to complete */
- thread_wait_finish();
+/**
+ * Check if this Thread is waiting (blocking) on a given Thread, directly or
+ * indirectly (via a chain of waiting threads)
+ *
+ * @param t The Thread on which we may be waiting
+ * @return True if we are waiting on Thread t; false otherwise
+ */
+bool Thread::is_waiting_on(const Thread *t) const
+{
+ Thread *wait;
- model->print_trace();
- delete th;
- delete model;
+ // One thread relocks a recursive mutex
+ if (waiting_on() == t && pending->is_lock()) {
+ int mutex_type = pending->get_mutex()->get_state()->type;
+ if (mutex_type == PTHREAD_MUTEX_RECURSIVE)
+ return false;
+ }
- DEBUG("Exiting\n");
- return 0;
+ for (wait = waiting_on();wait != NULL;wait = wait->waiting_on())
+ if (wait == t)
+ return true;
+ return false;
}
projects / c11tester.git / blobdiff